Board-to-board connector

ABSTRACT

A connector includes a rectangular flat-plate housing including a first positioning hole and a second positioning hole, and a contact row and a contact row held on the housing. The housing includes a first pitch side surface and a second pitch side surface on an opposite side of the first pitch side surface. The contact row and the contact row extend from the first pitch side surface to the second pitch side surface. The first positioning hole is disposed between the first pitch side surface and the contact row, and the second positioning hole is disposed between the first pitch side surface and the contact row.

INCORPORATION BY REFERENCE

This application is a continuation of U.S. patent application Ser. No.17/184,838, filed on Feb. 25, 2021, which is based upon and claims thebenefit of priority from Japanese patent application No. 2020-058408,filed on Mar. 27, 2020. The disclosures of the foregoing applicationsare incorporated herein in their entireties by reference.

BACKGROUND

The present disclosure relates to a board-to-board connector.

Patent Literature 1 (Japanese Unexamined Patent Application PublicationNo. 2010-182551) discloses a connector 100 that is disposed between afirst printed board having a plurality of electrodes and a secondprinted board having a plurality of electrodes, and electricallyconnects the plurality of electrodes of the first printed board with theplurality of electrodes of the second printed board respectively asshown in FIG. 20 of the present application.

The connector 100 includes an insulating plate 101 and a plurality ofelastic conductors 102 that are held on the insulating plate 101. Theinsulating plate 101 has two positioning holes 103.

SUMMARY

The connector 100 disclosed in Patent Literature 1 has room forimprovement in terms of size reduction.

An object of the present disclosure is to provide a technique to reducethe size of a board-to-board connector.

According to an aspect of the present invention, there is provided aboard-to-board connector to be mounted on a first board and interposedbetween the first board and a second board to electrically connect aplurality of pads of the first board with a plurality of pads of thesecond board respectively, the board-to-board connector including arectangular flat-plate housing including a first positioning hole and asecond positioning hole, and a first contact row and a second contactrow held on the housing, wherein the housing includes a first sidesurface on one side thereof and a second side surface on another sidethereof opposite to the one side, the first contact row and the secondcontact row extend from the first side surface to the second sidesurface, the first positioning hole is disposed between the first sidesurface and the first contact row, and the second positioning hole isdisposed between the first side surface and the second contact row.

According to the present disclosure, the size reduction of aboard-to-board connector is achieved.

The above and other objects, features and advantages of the presentdisclosure will become more fully understood from the detaileddescription given hereinbelow and the accompanying drawings which aregiven by way of illustration only, and thus are not to be considered aslimiting the present disclosure.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is an exploded perspective view of an information processingdevice (first embodiment);

FIG. 2 is an exploded perspective view of the information processingdevice viewed from another angle (first embodiment);

FIG. 3 is a perspective view of a connector (first embodiment);

FIG. 4 is an exploded perspective view of the connector (firstembodiment);

FIG. 5 is a perspective view of a housing (first embodiment);

FIG. 6 is a plan view showing the connector where hold-downs are omitted(first embodiment);

FIG. 7 is a plan view of the connector (first embodiment);

FIG. 8 is an enlarged view of a part A in FIG. 7 (first embodiment);

FIG. 9 is an enlarged view of a part B in FIG. 7 (first embodiment);

FIG. 10 is a partially cutout perspective view of the housing to which acontact is attached (first embodiment);

FIG. 11 is a partially cutout perspective view of the housing (firstembodiment);

FIG. 12 is a partial cross-sectional view of the housing to which thecontact is attached (first embodiment);

FIG. 13 is a perspective view of the contact (first embodiment);

FIG. 14 is an exploded perspective view of the connector with a suctioncover (first embodiment);

FIG. 15 is a partial perspective view of the connector with a suctioncover (first embodiment);

FIG. 16 is a partial perspective view of a connector with a suctioncover (second embodiment);

FIG. 17 is a partial cross-sectional view of a housing to which acontact is attached (third embodiment);

FIG. 18 is an exploded perspective view of a connector (fourthembodiment);

FIG. 19 is an exploded perspective view of a connector (fifthembodiment); and

FIG. 20 is a view showing a simplified version of FIG. 2 of JapaneseUnexamined Patent Application Publication No. 2010-182551.

DESCRIPTION OF EMBODIMENTS First Embodiment

A first embodiment is described hereinafter with reference to FIGS. 1 to15.

FIGS. 1 and 2 are exploded perspective views of an informationprocessing device 200. As shown in FIGS. 1 and 2, the informationprocessing device 200 includes a CPU board 201, a connector 202, aninput-output board 203, and a support board 204. The connector 202 isdisposed between the CPU board 201 and the input-output board 203.

The CPU board 201 and the input-output board 203 are rigid boards suchas a paper phenolic board or a glass epoxy board, for example.

As shown in FIG. 2, the CPU board 201 includes a connector opposedsurface 201A to be opposed to the connector 202. A plurality of pad rows205 are formed on the connector opposed surface 201A. In thisembodiment, six pad rows 205 are formed. The plurality of pad rows 205extend parallel to one another. The plurality of pad rows 205 are linedup in a direction orthogonal to a direction in which one of the pad rows205 extends. Each of the pad rows 205 includes a plurality of pads 206.

The CPU board 201 has a first bolt fastening hole 207, a second boltfastening hole 208, a first positioning hole 209, and a secondpositioning hole 210. The first bolt fastening hole 207 and the secondbolt fastening hole 208 are formed in such a way that the plurality ofpad rows 205 are located between the first bolt fastening hole 207 andthe second bolt fastening hole 208 in the longitudinal direction of eachpad row 205. The first positioning hole 209 and the second positioninghole 210 are formed to be adjacent to the first bolt fastening hole 207in the direction orthogonal to the longitudinal direction of each padrow 205. The first positioning hole 209 and the second positioning hole210 are formed in such a way that the first bolt fastening hole 207 islocated between the first positioning hole 209 and the secondpositioning hole 210 in the direction orthogonal to the longitudinaldirection of each pad row 205.

As shown in FIG. 1, the input-output board 203 includes a connectoropposed surface 203A to be opposed to the connector 202. A plurality ofpad rows 214 are formed on the connector opposed surface 203A. In thisembodiment, six pad rows 214 are formed. The plurality of pad rows 214extend parallel to one another. The plurality of pad rows 214 are linedup in a direction orthogonal to a direction in which one of the pad rows214 extends. Each of the pad rows 214 includes a plurality of pads 215.Further, a plurality of pads 216 for hold-down are formed on theconnector opposed surface 203A.

The input-output board 203 has a first bolt fastening hole 217, a secondbolt fastening hole 218, a first penetrating hole 219, and a secondpenetrating hole 220. The first bolt fastening hole 217 and the secondbolt fastening hole 218 are formed in such a way that the plurality ofpad rows 214 are located between the first bolt fastening hole 217 andthe second bolt fastening hole 218 in the longitudinal direction of eachpad row 214. The first penetrating hole 219 and the second penetratinghole 220 are formed to be adjacent to the first bolt fastening hole 217in the direction orthogonal to the longitudinal direction of each padrow 214. The first penetrating hole 219 and the second penetrating hole220 are formed in such a way that the first bolt fastening hole 217 islocated between the first penetrating hole 219 and the secondpenetrating hole 220 in the direction orthogonal to the longitudinaldirection of each pad row 214.

The support board 204 is typically a part of a casing that accommodatesthe CPU board 201, the connector 202, and the input-output board 203,and it is made of aluminum or aluminum alloy, for example. The supportboard 204 includes a flat-plate board main body 230, a first nut 231, asecond nut 232, a cylindrical first positioning pin 233, and acylindrical second positioning pin 234.

The first nut 231 is disposed to correspond to the first bolt fasteninghole 217 of the input-output board 203.

The second nut 232 is disposed to correspond to the second boltfastening hole 218 of the input-output board 203.

The cylindrical first positioning pin 233 is disposed to correspond tothe first penetrating hole 219 of the input-output board 203.

The cylindrical second positioning pin 234 is disposed to correspond tothe second penetrating hole 220 of the input-output board 203.

The connector 202 is surface-mountable by soldering on the connectoropposed surface 203A of the input-output board 203. As shown in FIGS. 3and 4, the connector 202 includes a rectangular flat-plate housing 250made of insulating resin, a plurality of contact rows 251, a firsthold-down 252, a second hold-down 253, a third hold-down 254, and afourth hold-down 255. The plurality of contact rows 251, the firsthold-down 252, the second hold-down 253, the third hold-down 254, andthe fourth hold-down 255 are held on the housing 250.

As shown in FIGS. 3 and 4, the plurality of contact rows 251 extendparallel to one another. The plurality of contact rows 251 are lined upin a direction orthogonal to a direction in which one of the contactrows 251 extends. As shown in FIG. 4, the plurality of contact rows 251include six contact rows 251. The six contact rows 251 include a contactrow 251A, a contact row 251B, a contact row 251C, a contact row 251D, acontact row 251E, and a contact row 251F. Each contact row 251 includesa plurality of contacts 300 made of metal.

Each contact 300 is formed by punching and bending a metal plate formedby plating copper or copper alloy, for example. Likewise, the firsthold-down 252, the second hold-down 253, the third hold-down 254, andthe fourth hold-down 255 are formed by punching and bending a metalplate such as a stainless steel plate, for example.

The terms “vertical direction”, “pitch direction” and “width direction”are defined by referring to FIG. 1 The vertical direction, the pitchdirection and the width direction are directions that are orthogonal toone another.

As shown in FIG. 1, the vertical direction is the thickness direction ofthe housing 250. The vertical direction includes upward and downward.The upward direction is the direction of viewing the CPU board 201 fromthe housing 250. The downward direction is the direction of viewing theinput-output board 203 from the housing 250. The vertical direction isthe direction used by way of illustration only and should not beinterpreted as limiting the posture of the connector 202 when it isactually used.

The pitch direction is the longitudinal direction of each contact row251.

The width direction is the direction orthogonal to the verticaldirection and the pitch direction. The plurality of contact rows 251 aredisposed to separate from each other in the width direction.

FIG. 5 shows the housing 250. As shown in FIG. 5, the housing 250includes a CPU board opposed surface 250A that is opposed to the CPUboard 201 by facing upward, and an input-output board opposed surface250B that is opposed to the input-output board 203 by facing downward.The housing 250 has a first positioning hole 260 and a secondpositioning hole 261. The first positioning hole 260 and the secondpositioning hole 261 are formed to penetrate the housing 250 in thevertical direction.

Referring back to FIG. 1, the overview of the assembly procedure of theinformation processing device 200 is described.

First, the connector 202 is surface-mounted on the input-output board203. To be specific, the plurality of contact rows 251 are soldered tothe plurality of pad rows 214, and further the first hold-down 252 andthe like are soldered to the corresponding pads 216.

Next, the input-output board 203 on which the connector 202 is mountedis attached to the support board 204. At this time, the first nut 231penetrates the first bolt fastening hole 217, and the second nut 232penetrates the second bolt fastening hole 218. Likewise, the firstpositioning pin 233 penetrates the first penetrating hole 219 and thefirst positioning hole 260 in this recited order, and the secondpositioning pin 234 penetrates the second penetrating hole 220 and thesecond positioning hole 261 in this recited order.

Then, the CPU board 201 is attached to the support board 204 in such away that the CPU board 201 overlaps the connector 202. At this time, thefirst positioning pin 233 penetrates the first positioning hole 209, andthe second positioning pin 234 penetrates the second positioning hole210. In this state, a first bolt 211 is fastened to the first nut 231through the first bolt fastening hole 207, and a second bolt 212 isfastened to the second nut 232 through the second bolt fastening hole208. In this manner, the connector 202 is interposed between the CPUboard 201 and the input-output board 203, and thereby the plurality ofpads 215 of the input-output board 203 and the plurality of pads 206 ofthe CPU board 201 are respectively electrically connected through theplurality of contacts 300.

Further, the first positioning pin 233 is inserted into the firstpositioning hole 260 of the connector 202 and the first positioning hole209 of the CPU board 201, and the second positioning pin 234 is insertedinto the second positioning hole 261 of the connector 202 and the secondpositioning hole 210 of the CPU board 201, and thereby highly accuratepositioning of the CPU board 201 with respect to the connector 202 isachieved.

The connector 202 is described hereinafter in further detail.

As shown in FIG. 5, the housing 250 is formed in a rectangularflat-plate shape. Specifically, the housing 250 includes a first pitchside surface 262, a second pitch side surface 263, a first width sidesurface 264, and a second width side surface 265. The first pitch sidesurface 262 and the second pitch side surface 263 are side surfacesorthogonal to the pitch direction. The first pitch side surface 262 andthe second pitch side surface 263 are surfaces opposed to each other.The first width side surface 264 and the second width side surface 265are side surfaces orthogonal to the width direction. The first widthside surface 264 and the second width side surface 265 are surfacesopposed to each other.

The housing 250 further includes a first corner part 266, a secondcorner part 267, a third corner part 268, and a fourth corner part 269.The first corner part 266 is a corner at which the first pitch sidesurface 262 and the first width side surface 264 intersect. The secondcorner part 267 is a corner at which the first pitch side surface 262and the second width side surface 265 intersect. The third corner part268 is a corner at which the second pitch side surface 263 and the firstwidth side surface 264 intersect. The fourth corner part 269 is a cornerat which the second pitch side surface 263 and the second width sidesurface 265 intersect. Thus, the first corner part 266 and the fourthcorner part 269 are located at diagonal positions of the rectangularhousing 250 when viewed from above. Likewise, the second corner part 267and the third corner part 268 are located at diagonal positions of therectangular housing 250 when viewed from above. The above-describedfirst positioning hole 260 is formed at the first corner part 266. Thesecond positioning hole 261 is formed at the second corner part 267. Thehousing 250 has only two positioning holes.

On the first pitch side surface 262, a first hold-down press-fit groove270, a first nut notch 271, and a second hold-down press-fit groove 272are formed in this recited order from the first width side surface 264to the second width side surface 265.

On the second pitch side surface 263, a third hold-down press-fit groove273, a second nut notch 274, a fourth hold-down press-fit groove 275 areformed in this recited order from the first width side surface 264 tothe second width side surface 265.

On the CPU board opposed surface 250A, a first hold-down accommodationrecess 280, a second hold-down accommodation recess 281, a thirdhold-down accommodation recess 282, and a fourth hold-down accommodationrecess 283 are formed.

On the housing 250, a plurality of contact accommodation parts 284 arefurther formed.

The first hold-down press-fit groove 270 is a groove for holding thefirst hold-down 252 by press-fitting.

The second hold-down press-fit groove 272 is a groove for holding thesecond hold-down 253 by press-fitting.

The third hold-down press-fit groove 273 is a groove for holding thethird hold-down 254 by press-fitting.

The fourth hold-down press-fit groove 275 is a groove for holding thefourth hold-down 255 by press-fitting.

The first nut notch 271 is a notch for avoiding the physicalinterference between the first nut 231 and the housing 250. In order toavoid the physical interference between the first nut 231 and thehousing 250 shown in FIG. 1, the housing 250 may be provided with a holethat allows the first nut 231 to penetrate, instead of the first nutnotch 271.

The second nut notch 274 is a notch for avoiding the physicalinterference between the second nut 232 and the housing 250 shown inFIG. 1. In order to avoid the physical interference between the secondnut 232 and the housing 250 shown in FIG. 1, it is feasible to form ahole for the second nut 232 to penetrate on the housing 250 rather thanforming the second nut notch 274 on the housing 250.

Referring back to FIG. 5, the first hold-down accommodation recess 280is formed to accommodate the first hold-down 252 so that the firsthold-down 252 attached to the housing 250 does not come closer to theCPU board 201 beyond the CPU board opposed surface 250A. The firsthold-down accommodation recess 280 is formed at the first corner part266. The first hold-down accommodation recess 280 is formed to surroundthe first positioning hole 260 when viewed from above. The depth of thefirst hold-down accommodation recess 280 is greater than the thicknessof the first hold-down 252.

The second hold-down accommodation recess 281 is formed to accommodatethe second hold-down 253 so that the second hold-down 253 attached tothe housing 250 does not come closer to the CPU board 201 beyond the CPUboard opposed surface 250A. The second hold-down accommodation recess281 is formed at the second corner part 267. The second hold-downaccommodation recess 281 is formed to surround the second positioninghole 261 when viewed from above. The depth of the second hold-downaccommodation recess 281 is greater than the thickness of the secondhold-down 253.

The third hold-down accommodation recess 282 is formed to accommodatethe third hold-down 254 so that the third hold-down 254 attached to thehousing 250 does not come closer to the CPU board 201 beyond the CPUboard opposed surface 250A. The third hold-down accommodation recess 282is formed at the third corner part 268. The depth of the third hold-downaccommodation recess 282 is greater than the thickness of the thirdhold-down 254.

The fourth hold-down accommodation recess 283 is formed to accommodatethe fourth hold-down 255 so that the fourth hold-down 255 attached tothe housing 250 does not come closer to the CPU board 201 beyond the CPUboard opposed surface 250A. The fourth hold-down accommodation recess283 is formed at the fourth corner part 269. The depth of the fourthhold-down accommodation recess 283 is greater than the thickness of thefourth hold-down 255.

Each of the contact accommodation parts 284 is a part that accommodateseach of the contacts 300. Each of the contact accommodation parts 284 isformed to penetrate the housing 250 in the vertical direction.

FIG. 6 shows the connector 202 viewed from above. Note that, however,the first hold-down 252, the second hold-down 253, the third hold-down254, and the fourth hold-down 255 are not shown for the sake ofconvenience of description.

As shown in FIG. 6, the first hold-down press-fit groove 270 and thelike are formed on the first pitch side surface 262. Thus, the firstpitch side surface 262 exists in a discontinuous manner in the widthdirection. For the following description, a part of the first pitch sidesurface 262 which is missing due to the formation of the first hold-downpress-fit groove 270 or the like is indicated by a chain double-dashedline, and the first pitch side surface 262 is specified by drawing aleader line of the first pitch side surface 262 from this chaindouble-dashed line.

Likewise, the third hold-down press-fit groove 273 and the like areformed on the second pitch side surface 263. Thus, the second pitch sidesurface 263 exists in a discontinuous manner in the width direction. Forthe following description, a part of the second pitch side surface 263which is missing due to the formation of the third hold-down press-fitgroove 273 or the like is indicated by a chain double-dashed line, andthe second pitch side surface 263 is specified by drawing a leader lineof the second pitch side surface 263 from this chain double-dashed line.

As shown in FIG. 6, the plurality of contact rows 251 are disposed to besymmetric with respect to a halving line 250C that divides the housing250 into two halves. Among the plurality of contact rows 251, particularattention is focused on a contact row 251A, a contact row 251D, and acontact row 251F.

The contact row 251A, the contact row 251D, and the contact row 251Fextend from the first pitch side surface 262 to the second pitch sidesurface 263.

The first positioning hole 260 is adjacent to the contact row 251A inthe pitch direction. The first positioning hole 260 is disposed betweenthe first pitch side surface 262 indicated by the chain double-dashedline and the contact row 251A.

Likewise, the second positioning hole 261 is adjacent to the contact row251F in the pitch direction. The second positioning hole 261 is disposedbetween the first pitch side surface 262 indicated by the chaindouble-dashed line and the contact row 251F.

The distance between the contact row 251A and the first pitch sidesurface 262 in the pitch direction is defined as a distance D1.Specifically, the distance D1 is the distance between the contact 300that is closest to the first pitch side surface 262 among the pluralityof contacts 300 forming the contact row 251A and the first pitch sidesurface 262.

Likewise, the distance between the contact row 251F and the first pitchside surface 262 in the pitch direction is defined as a distance D2.Specifically, the distance D2 is the distance between the contact 300that is closest to the first pitch side surface 262 among the pluralityof contacts 300 forming the contact row 251F and the first pitch sidesurface 262.

Likewise, the distance between the contact row 251D and the first pitchside surface 262 in the pitch direction is defined as a distance D3.Specifically, the distance D3 is the distance between the contact 300that is closest to the first pitch side surface 262 among the pluralityof contacts 300 forming the contact row 251D and the first pitch sidesurface 262.

In this embodiment, the relationship of D1=D2 is established. Further,in this embodiment, the relationships of D3<D1 and D3<D2 areestablished. In simpler terms, the contact row 251D is closer to thefirst pitch side surface 262 than the contact row 251A is, and is alsocloser to the first pitch side surface 262 than the contact row 251F is.

The first nut notch 271 is open to the first pitch side surface 262indicated by the chain double-dashed line, and formed between the firstpitch side surface 262 indicated by the chain double-dashed line and thecontact row 251D.

The distance between the contact row 251A and the second pitch sidesurface 263 in the pitch direction is defined as a distance E1.Specifically, the distance E1 is the distance between the contact 300that is closest to the second pitch side surface 263 among the pluralityof contacts 300 forming the contact row 251A and the second pitch sidesurface 263.

Likewise, the distance between the contact row 251F and the second pitchside surface 263 in the pitch direction is defined as a distance E2.Specifically, the distance E2 is the distance between the contact 300that is closest to the second pitch side surface 263 among the pluralityof contacts 300 forming the contact row 251F and the second pitch sidesurface 263.

Likewise, the distance between the contact row 251D and the second pitchside surface 263 in the pitch direction is defined as a distance E3.Specifically, the distance E3 is the distance between the contact 300that is closest to the second pitch side surface 263 among the pluralityof contacts 300 forming the contact row 251D and the second pitch sidesurface 263.

In this embodiment, the relationship of E1=E2 is established. Further,in this embodiment, the relationships of E3>E1 and E3>E2 areestablished. In simpler terms, the contact row 251D is farther from thesecond pitch side surface 263 than the contact row 251A is, and is alsofarther from the second pitch side surface 263 than the contact row 251Fis.

The second nut notch 274 is open to the second pitch side surface 263indicated by the chain double-dashed line, and formed between the secondpitch side surface 263 indicated by the chain double-dashed line and thecontact row 251D.

The first positioning hole 260, the second positioning hole 261, thefirst hold-down 252, the second hold-down 253, the third hold-down 254,and the fourth hold-down 255 are hereinafter described in further detailwith reference to FIGS. 7 to 9. FIG. 8 is an enlarged view of the part Ain FIG. 7. FIG. 9 is an enlarged view of the part B in FIG. 7.

As shown in FIG. 8, the first positioning hole 260 is a round hole thatpenetrates the housing 250 in the vertical direction, and it has aninner edge 260A.

The first hold-down 252 includes a reinforcing plate part 252A and twosoldering parts 252B.

The reinforcing plate part 252A is disposed to cover the CPU boardopposed surface 250A around the first positioning hole 260. Thereinforcing plate part 252A is accommodated in the first hold-downaccommodation recess 280 that is formed on the CPU board opposed surface250A. Thus, the reinforcing plate part 252A is farther from the CPUboard 201 than a part 250D of the CPU board opposed surface 250A inwhich the first hold-down accommodation recess 280 is not formed, whilecovering the CPU board opposed surface 250A. Therefore, the elasticdeformation of each contact 300 is not hindered when pressing the CPUboard 201 against the connector 202.

Each of the soldering parts 252B projects from the reinforcing platepart 252A toward the input-output board 203 and is connectable bysoldering to the corresponding pad 216 of the input-output board 203.One of the two soldering parts 252B is press-fit into the firsthold-down press-fit groove 270 formed on the first pitch side surface262, and thereby the first hold-down 252 is held by the housing 250.Each of the soldering parts 252B projects downward beyond theinput-output board opposed surface 250B of the housing 250 shown in FIG.5.

Referring back to FIG. 8, the reinforcing plate part 252A has apenetrating hole 252C. The penetrating hole 252C is a round hole thatpenetrates the reinforcing plate part 252A in the vertical direction,and it has an inner edge 252D.

The penetrating hole 252C is larger than the first positioning hole 260.To be specific, an inside diameter 252E of the penetrating hole 252C isgreater than an inside diameter 260B of the first positioning hole 260.

The first hold-down 252 is disposed in such a way that the reinforcingplate part 252A does not cover the inner edge 260A of the firstpositioning hole 260 when viewed from above. Specifically, the firsthold-down 252 is disposed in such a way that the inner edge 260A of thefirst positioning hole 260 is located radially inward with respect tothe inner edge 252D of the penetrating hole 252C when viewed from above.

The reinforcing plate part 252A made of metal thereby does not hinderthe positioning function of the inner edge 260A of the first positioninghole 260 and the first positioning pin 233. Further, the reinforcingplate part 252A made of metal reduces the degree of deformation when thefirst positioning hole 260 is deformed outward in the radial directiondue to contact with the first positioning pin 233, which avoids asignificant decrease in positioning accuracy of the positioningfunction.

As shown in FIG. 9, the second positioning hole 261 is a slotted holethat penetrates the housing 250 in the vertical direction. The secondpositioning hole 261 extends to come closer to the first positioninghole 260. The second positioning hole 261 is elongated in the widthdirection. The second positioning hole 261 has an inner edge 261A.

The second hold-down 253 includes a reinforcing plate part 253A and twosoldering parts 253B.

The reinforcing plate part 253A is disposed to cover the CPU boardopposed surface 250A around the second positioning hole 261. Thereinforcing plate part 253A is accommodated in the second hold-downaccommodation recess 281 that is formed on the CPU board opposed surface250A. Thus, the reinforcing plate part 253A is farther from the CPUboard 201 than the part 250D of the CPU board opposed surface 250A inwhich the second hold-down accommodation recess 281 is not formed, whilecovering the CPU board opposed surface 250A. Therefore, the elasticdeformation of each contact 300 is not hindered when pressing the CPUboard 201 against the connector 202.

Each of the soldering parts 253B projects from the reinforcing platepart 253A toward the input-output board 203 and is connectable bysoldering to the corresponding pad 216 of the input-output board 203.One of the two soldering parts 253B is press-fit into the secondhold-down press-fit groove 272 formed on the first pitch side surface262, and thereby the second hold-down 253 is held by the housing 250.Each of the soldering parts 253B projects downward beyond theinput-output board opposed surface 250B of the housing 250 shown in FIG.5.

Referring back to FIG. 9, the reinforcing plate part 253A has apenetrating hole 253C. The penetrating hole 253C is a slotted hole thatpenetrates the reinforcing plate part 253A in the vertical direction,and it has an inner edge 253D.

The penetrating hole 253C is larger than the second positioning hole261. To be specific, the inner edge 253D of the penetrating hole 253Chas two straight edge parts 253E that are opposed to each other in thepitch direction. The inner edge 261A of the second positioning hole 261has two straight edge parts 261B that are opposed to each other in thepitch direction. A distance 253F between the two straight edge parts253E is longer than a distance 261C between the two straight edge parts261B.

The second hold-down 253 is disposed in such a way that the reinforcingplate part 253A does not cover the inner edge 261A of the secondpositioning hole 261 when viewed from above. Specifically, the secondhold-down 253 is disposed in such a way that the inner edge 261A of thesecond positioning hole 261 is located inward with respect to the inneredge 253D of the penetrating hole 253C when viewed from above. To bespecific, the second hold-down 253 is disposed in such a way that thetwo straight edge parts 261B are located between the two straight edgeparts 253E.

The reinforcing plate part 253A made of metal thereby does not hinderthe positioning function of the inner edge 261A of the secondpositioning hole 261 and the second positioning pin 234. Further, thereinforcing plate part 253A made of metal reduces the degree ofdeformation when the second positioning hole 261 is deformed outward dueto contact with the second positioning pin 234, which avoids asignificant decrease in positioning accuracy of the positioningfunction.

As shown in FIG. 4, in this embodiment, while the housing 250 is formedintegrally, the first hold-down 252 and the second hold-down 253 areseparate parts. Thus, referring to FIGS. 7 to 9, the relative positionalrelationship between the first positioning hole 260 and the secondpositioning hole 261 in the housing 250 is more easily manageablecompared with the relative positional relationship between thepenetrating hole 252C of the first hold-down 252 and the penetratinghole 253C of the second hold-down 253. Therefore, since the reinforcingplate part 252A of the first hold-down 252 does not cover the inner edge260A of the first positioning hole 260 when viewed from above as shownin FIG. 8 and the reinforcing plate part 253A of the second hold-down253 does not cover the inner edge 261A of the second positioning hole261 when viewed from above as shown in FIG. 9, the positioning functionby the first positioning hole 260 and the second positioning hole 261 isreliably exerted, which achieves high positioning accuracy of the CPUboard 201 with respect to the connector 202.

Referring back to FIG. 7, the third hold-down 254 includes a coveringplate part 254A and two soldering parts 254B.

The covering plate part 254A is accommodated in the third hold-downaccommodation recess 282 that is formed on the CPU board opposed surface250A. Thus, the covering plate part 254A is farther from the CPU board201 than the part 250D of the CPU board opposed surface 250A in whichthe third hold-down accommodation recess 282 is not formed, whilecovering the CPU board opposed surface 250A. Therefore, the elasticdeformation of each contact 300 is not hindered when pressing the CPUboard 201 against the connector 202.

Each of the soldering parts 254B projects from the covering plate part254A toward the input-output board 203 and is connectable by solderingto the corresponding pad 216 of the input-output board 203. One of thetwo soldering parts 254B is press-fit into the third hold-down press-fitgroove 273 formed on the second pitch side surface 263, and thereby thethird hold-down 254 is held by the housing 250. Each of the solderingparts 254B projects downward beyond the input-output board opposedsurface 250B of the housing 250 shown in FIG. 5.

Referring back to FIG. 7, the fourth hold-down 255 includes a coveringplate part 255A and two soldering parts 255B.

The covering plate part 255A is accommodated in the fourth hold-downaccommodation recess 283 that is formed on the CPU board opposed surface250A. Thus, the covering plate part 255A is farther from the CPU board201 than the part 250D of the CPU board opposed surface 250A in whichthe fourth hold-down accommodation recess 283 is not formed, whilecovering the CPU board opposed surface 250A. Therefore, the elasticdeformation of each contact 300 is not hindered when pressing the CPUboard 201 against the connector 202.

Each of the soldering parts 255B projects from the covering plate part255A toward the input-output board 203 and is connectable by solderingto the corresponding pad 216 of the input-output board 203. One of thetwo soldering parts 255B is press-fit into the fourth hold-downpress-fit groove 275 formed on the second pitch side surface 263, andthereby the fourth hold-down 255 is held by the housing 250. Each of thesoldering parts 255B projects downward beyond the input-output boardopposed surface 250B of the housing 250 shown in FIG. 5.

Each of the contacts 300 and each of the contact accommodation parts 284are described hereinafter in detail with reference to FIGS. 10 to 13.

As shown in FIGS. 10 and 11, each contact accommodation part 284 isformed to attach each contact 300 to the housing 250. As shown in FIG.11, each contact accommodation part 284 is composed of a press-fittingspace 301, a solder connection checking hole 302, and a separating wall303. The press-fitting space 301 and the solder connection checking hole302 are formed separately from each other in the width direction. Theseparating wall 303 is a wall that separates the press-fitting space 301from the solder connection checking hole 302 in the width direction.

The press-fitting space 301 is formed as a penetrating hole thatpenetrates the housing 250 in the vertical direction. Specifically, thepress-fitting space 301 is open to the CPU board opposed surface 250Aand the input-output board opposed surface 250B. The housing 250includes, for each press-fitting space 301, two pitch partition surfaces304 that partitions the press-fitting space 301 in the pitch direction.FIG. 11 shows only one of the two pitch partition surfaces 304. In FIG.12, the cross-sectional shapes of the press-fitting space 301 and thesolder connection checking hole 302 are specified by chain double-dashedlines. As shown in FIG. 12, a press-fit groove 305 that extends in thevertical direction is formed on each pitch partition surface 304. Eachpitch partition surface 304 includes a press-fit surface 305A thatpartitions the press-fit groove 305 in the pitch direction.

Referring back to FIG. 11, the solder connection checking hole 302 is apenetrating hole that penetrates the housing 250 in the verticaldirection. Specifically, the solder connection checking hole 302 is opento the CPU board opposed surface 250A and the input-output board opposedsurface 250B.

The separating wall 303 is a wall that spatially separates thepress-fitting space 301 from the solder connection checking hole 302 asdescribed above, and it is formed between the press-fitting space 301and the solder connection checking hole 302. As shown in FIG. 12, theseparating wall 303 includes a first separating surface 306 thatpartitions the press-fitting space 301 in the width direction, and asecond separating surface 307 that partitions the solder connectionchecking hole 302 in the width direction. The first separating surface306 and the second separating surface 307 are surfaces orthogonal to thewidth direction. As shown in FIGS. 11 and 12, the separating wall 303has a notch 308 that is open to the press-fitting space 301 and thesolder connection checking hole 302 and is also open to the input-outputboard opposed surface 250B. The notch 308 is formed at the lower end ofthe separating wall 303.

FIG. 13 is a perspective view of each contact 300. As shown in FIG. 13,each contact 300 includes a press-fit part 320, a soldering part 321,and an electrical contact spring piece 322.

The press-fit part 320 is a part to be press-fit into the press-fittingspace 301 shown in FIG. 12. Specifically, the press-fit part 320 ispress-fit into the press-fitting space 301, and thereby each contact 300is held by the housing 250. Referring back to FIG. 13, the press-fitpart 320 is a plate body that is orthogonal to the width direction, andit includes a press-fit part main body 323 and two press-fit claws 324.The two press-fit claws 324 are formed to project in the pitch directionfrom the both ends of the press-fit part main body 323 in the pitchdirection.

The soldering part 321 is a part that is connectable by soldering to thecorresponding pad 215 of the input-output board 203 shown in FIG. 1. Asshown in FIG. 13, the soldering part 321 includes a horizontal extensionpart 321A that extends in the width direction from the lower end of thepress-fit part 320 and a curve part 321B that curves upward from thehorizontal extension part 321A.

The electrical contact spring piece 322 is a part that functions as anelectrical contact point of the CPU board 201 shown in FIG. 2 with thecorresponding pad 206. As shown in FIG. 13, the electrical contactspring piece 322 includes a spring piece joining part 325, an easilyelastically deformable part 326, and a contact part 327. The springpiece joining part 325, the easily elastically deformable part 326, andthe contact part 327 are continuous in this recited order.

The spring piece joining part 325 extends downward from the upper end ofthe press-fit part 320.

The easily elastically deformable part 326 extends from the lower end ofthe spring piece joining part 325 and is formed in a U-shape that isconvex in the width direction. Specifically, the easily elasticallydeformable part 326 includes a lower straight part 326A, a curve part326B, and an upper straight part 326C. The lower straight part 326A, thecurve part 326B, and the upper straight part 326C are continuous in thisrecited order. The lower straight part 326A and the upper straight part326C are opposed to each other in the vertical direction. The lowerstraight part 326A and the upper straight part 326C are joined throughthe curve part 326B.

The contact part 327 is a part that can come into electrical contactwith the corresponding pad 206 of the CPU board 201 shown in FIG. 2. Thecontact part 327 is placed at the end of the upper straight part 326C ofthe easily elastically deformable part 326, and it is formed to curve tobe convex upward.

FIG. 12 shows the state where each contact 300 is attached to eachcontact accommodation part 284. In order to attach each contact 300 toeach contact accommodation part 284, each contact 300 is press-fit intothe press-fitting space 301 of each contact accommodation part 284 fromthe input-output board opposed surface 250B side. At this time, the twopress-fit claws 324 of the press-fit part 320 shown in FIG. 13respectively bite into the two pitch partition surfaces 304. In moredetail, each of the two press-fit claws 324 of the press-fit part 320shown in FIG. 13 bites into the press-fit surface 305A of the press-fitgroove 305 formed on the two pitch partition surfaces 304.

When each contact 300 is attached to each contact accommodation part284, the easily elastically deformable part 326 is accommodated in thepress-fitting space 301, and the contact part 327 thereby projectsupward from the CPU board opposed surface 250A. Further, the solderingpart 321 passes through the notch 308 and reaches the solder connectionchecking hole 302. In more detail, the horizontal extension part 321A ofthe soldering part 321 extends in the width direction inside the notch308, and the curve part 321B is located in the solder connectionchecking hole 302. In this state, while the press-fit part 320 comesinto contact with the separating wall 303 of the housing 250, thesoldering part 321 and the electrical contact spring piece 322 do notcome into contact with the housing 250.

FIG. 12 shows the state where the soldering part 321 is connected bysoldering to the corresponding pad 215 of the input-output board 203. Asshown in FIG. 12, when the soldering part 321 is connected by solderingto the pad 215, a solder fillet 330 is formed between the curve part321B of the soldering part 321 and the pad 215. In general, thesoldering part 321 is regarded as being normally soldered to the pad 215upon formation of the solder fillet 330. Thus, in this embodiment, thehousing 250 is provided with the solder connection checking hole 302, sothat the presence of the solder fillet 330 is checked from above throughthe solder connection checking hole 302. This enables determiningwhether the solder connection of each contact 300 is successfully madeor not after surface-mounting the connector 202 onto the input-outputboard 203.

In this embodiment, the separating wall 303 that separates thepress-fitting space 301 from the solder connection checking hole 302 isformed as described above. The presence of the separating wall 303prevents shavings of the housing 250, which can be generated whenpress-fitting the press-fit part 320 into the press-fitting space 301,from moving into the solder connection checking hole 302. This allowschecking the solder fillet 330 from above through the solder connectionchecking hole 302 with no problem.

Hereinafter, a connector 202A with a suction cover is described withreference to FIGS. 14 and 15. The connector 202A with a suction coverincludes a connector 202 and a suction cover 340 that is detachable fromthe connector 202. As shown in FIGS. 14 and 15, the suction cover 340 istemporarily attached to the connector 202 in order to hold the connector202 by a suction nozzle, which is not shown, when surface-mounting theconnector 202 onto the input-output board 203.

As shown in FIG. 14, the suction cover 340 includes a suction plate part341, a plurality of attachment spring pieces 342, a plurality of maindeformation restraining parts 343, and two removal hooks 344. Thesuction cover 340 is formed by punching and bending a metal plate suchas a stainless steel plate, for example.

The suction plate part 341 is a flat plate that covers and protects theelectrical contact spring piece 322 of each contact 300 and can besucked by a suction nozzle, which is not shown. The thickness directionof the suction plate part 341 is parallel to the vertical direction whenattached to the connector 202.

The plurality of attachment spring pieces 342 are configured to catch onthe connector 202 so that the suction plate part 341 is detachable fromthe connector 202. The plurality of attachment spring pieces 342 includea first attachment spring piece 345, a second attachment spring piece346, a third attachment spring piece 347, and a fourth attachment springpiece 348.

The first attachment spring piece 345 corresponds to the first cornerpart 266 in the state where the suction cover 340 is attached to theconnector 202.

Likewise, the second attachment spring piece 346 corresponds to thesecond corner part 267 in the state where the suction cover 340 isattached to the connector 202.

Likewise, the third attachment spring piece 347 corresponds to the thirdcorner part 268 in the state where the suction cover 340 is attached tothe connector 202.

Likewise, the fourth attachment spring piece 348 corresponds to thefourth corner part 269 in the state where the suction cover 340 isattached to the connector 202.

As shown in FIG. 15, the first pitch side surface 262 of the housing 250has a recess 285 and a recess 286. The recess 285 is disposed tocorrespond to the first corner part 266. The recess 286 is disposed tocorrespond to the second corner part 267.

The first attachment spring piece 345 includes a protrusion 345A, and aspring piece 345B that supports the protrusion 345A in such a way thatthe protrusion 345A is displaceable in the pitch direction. The secondattachment spring piece 346, the third attachment spring piece 347, andthe fourth attachment spring piece 348 have the same structure.

Referring back to FIG. 14, the plurality of main deformation restrainingparts 343 project from the suction plate part 341 toward the CPU boardopposed surface 250A in order to inhibit the suction plate part 341 frombeing deformed toward the CPU board opposed surface 250A in the statewhere the suction cover 340 is attached to the connector 202. Theplurality of main deformation restraining parts 343 include a first maindeformation restraining part 350, a second main deformation restrainingpart 351, a third main deformation restraining part 352, and a fourthmain deformation restraining part 353.

The first main deformation restraining part 350 corresponds to the firstcorner part 266 in the state where the suction cover 340 is attached tothe connector 202.

Likewise, the second main deformation restraining part 351 correspondsto the second corner part 267 in the state where the suction cover 340is attached to the connector 202.

Likewise, the third main deformation restraining part 352 corresponds tothe third corner part 268 in the state where the suction cover 340 isattached to the connector 202.

Likewise, the fourth main deformation restraining part 353 correspondsto the fourth corner part 269 in the state where the suction cover 340is attached to the connector 202.

The first main deformation restraining part 350 and the second maindeformation restraining part 351 are disposed between the firstattachment spring piece 345 and the second attachment spring piece 346.

The third main deformation restraining part 352 and the fourth maindeformation restraining part 353 are disposed between the thirdattachment spring piece 347 and the fourth attachment spring piece 348.

As shown in FIG. 15, the first main deformation restraining part 350 isformed by bending a part of the suction plate part 341 downward. Inother words, the first main deformation restraining part 350 is formedto project downward from the suction plate part 341. The first maindeformation restraining part 350 is disposed in such a way that a lowerend 350A of the first main deformation restraining part 350 is opposedto the reinforcing plate part 252A of the first hold-down 252 in thevertical direction in the state where the suction cover 340 is attachedto the connector 202.

Likewise, the second main deformation restraining part 351 is formed bybending a part of the suction plate part 341 downward. In other words,the second main deformation restraining part 351 is formed to projectdownward from the suction plate part 341. The second main deformationrestraining part 351 is disposed in such a way that a lower end 351A ofthe second main deformation restraining part 351 is opposed to thereinforcing plate part 253A of the second hold-down 253 in the verticaldirection in the state where the suction cover 340 is attached to theconnector 202.

As shown in FIG. 14, the third main deformation restraining part 352 isformed by bending a part of the suction plate part 341 downward. Inother words, the third main deformation restraining part 352 is formedto project downward from the suction plate part 341. The third maindeformation restraining part 352 is disposed in such a way that a lowerend of the third main deformation restraining part 352 is opposed to thecovering plate part 254A of the third hold-down 254 in the verticaldirection in the state where the suction cover 340 is attached to theconnector 202.

Likewise, the fourth main deformation restraining part 353 is formed bybending a part of the suction plate part 341 downward. In other words,the fourth main deformation restraining part 353 is formed to projectdownward from the suction plate part 341. The fourth main deformationrestraining part 353 is disposed in such a way that a lower end of thefourth main deformation restraining part 353 is opposed to the coveringplate part 255A of the fourth hold-down 255 in the vertical direction inthe state where the suction cover 340 is attached to the connector 202.

Thus, when the suction plate part 341 is deformed toward the CPU boardopposed surface 250A, the first main deformation restraining part 350and the second main deformation restraining part 351 come into contactwith the first hold-down 252 and the second hold-down 253, respectively,and the third main deformation restraining part 352 and the fourth maindeformation restraining part 353 come into contact with the thirdhold-down 254 and the fourth hold-down 255, respectively, therebyinhibiting the further deformation of the suction plate part 341. Thisprevents that the suction plate part 341 comes into contact with theelectrical contact spring piece 322 of the plurality of contacts 300 tocause the plurality of contacts 300 to be broken.

Further, the first main deformation restraining part 350 and the secondmain deformation restraining part 351 are configured to be received bythe first hold-down 252 and the second hold-down 253 respectively whenthe suction plate part 341 is deformed toward the CPU board opposedsurface 250A. Likewise, the third main deformation restraining part 352and the fourth main deformation restraining part 353 are configured tobe received by the third hold-down 254 and the fourth hold-down 255respectively when the suction plate part 341 is deformed toward the CPUboard opposed surface 250A. Thus, the first main deformation restrainingpart 350, the second main deformation restraining part 351, the thirdmain deformation restraining part 352, and the fourth main deformationrestraining part 353 do not come into direct contact with the CPU boardopposed surface 250A of the housing 250 when the suction plate part 341is deformed toward the CPU board opposed surface 250A. This effectivelyinhibits the collision of the first main deformation restraining part350, the second main deformation restraining part 351, the third maindeformation restraining part 352, and the fourth main deformationrestraining part 353 with the housing 250 to damage the housing 250 andinhibits the generation of shavings that can cause defective connection.

Note that, although the suction cover 340 includes a plurality of maindeformation restraining parts 343 in the description of this embodiment,it may include only one main deformation restraining part 343.

As shown in FIG. 14, the two removal hooks 344 project from the suctionplate part 341 in the width direction. Then, the two removal hooks 344are disposed to project outward beyond an outer edge 354 of theconnector 202 when viewed from above in the state where the suctioncover 340 is attached to the connector 202. This allows a thumb and aforefinger, for example, to easily catch on the two removal hooks 344,respectively, which facilitates the removal of the suction cover 340from the connector 202.

As shown in FIGS. 1 and 2, when the CPU board 201 is pressed against theconnector 202 by using the first bolt 211 and the second bolt 212 asdescribed above, the contact part 327 of the electrical contact springpiece 322 of each contact 300 shown in FIG. 12 is elastically displaceddownward, and then the connector opposed surface 201A of the CPU board201 shown in FIG. 2 comes into plane contact with the CPU board opposedsurface 250A of the housing 250 of the connector 202 shown in FIG. 3. Atthis time, the connector opposed surface 201A of the CPU board 201 isnot in contact with the first hold-down 252 and the like.

After that, when the CPU board 201 is further pressed against theconnector 202 by using the first bolt 211 and the second bolt 212, thehousing 250 moves downward relative to the first hold-down 252 and thelike, with the soldering part 252B shown in FIG. 8 sliding on the firsthold-down press-fit groove 270. Eventually, the connector opposedsurface 201A of the CPU board 201 is received by the first hold-down 252and the like that are soldered to the input-output board 203. Thisrestricts the downward movement of the housing 250 relative to the firsthold-down 252 and the like.

The first embodiment is described above, and the above-described firstembodiment has the following features.

First Technical Idea: No. 0170

As shown in FIGS. 1 and 2, the connector 202 (board-to-board connector)is mounted on the input-output board 203 (first board). The connector202 is interposed between the input-output board 203 and the CPU board201 (second board), and thereby the plurality of pads 215 of theinput-output board 203 and the plurality of pads 206 of the CPU board201 are respectively electrically connected. As shown in FIG. 6, theconnector 202 includes the rectangular flat-plate housing 250 having thefirst positioning hole 209 and the second positioning hole 210, and thecontact row 251A (first contact row) and the contact row 251F (secondcontact row) held on the housing 250. The housing 250 includes the firstpitch side surface 262 (first side surface) and the second pitch sidesurface 263 (second surface), which is an opposite side of the firstpitch side surface 262. The contact row 251A and the contact row 251Fextend from the first pitch side surface 262 to the second pitch sidesurface 263. The first positioning hole 260 is disposed between thefirst pitch side surface 262 and the contact row 251A, and the secondpositioning hole 261 is disposed between the first pitch side surface262 and the contact row 251F. In this structure, the first positioninghole 260 and the second positioning hole 261 are concentrated on thefirst pitch side surface 262 side, which contributes to the sizereduction of the connector 202.

Further, as shown in FIG. 6, the connector 202 further includes thecontact row 251D (third contact row) that is disposed between thecontact row 251A and the contact row 251F and extends from the firstpitch side surface 262 to the second pitch side surface 263. Thedistance D1 between the contact row 251A and the first pitch sidesurface 262, the distance D2 between the contact row 251F and the firstpitch side surface 262, and the distance D3 between the contact row 251Dand the first pitch side surface 262 satisfy the relationships of D3<D1and D3<D2. This structure enables an increase in the number of thecontacts 300 by utilizing the space between the first positioning hole260 and the second positioning hole 261.

Further, as shown in FIG. 6, the first nut notch 271 (notch) that isopen to the first pitch side surface 262 is formed between the firstpositioning hole 260 and the second positioning hole 261. This structureallows the first nut notch 271 to be formed by utilizing the spacebetween the first positioning hole 260 and the second positioning hole261, which contributes to the size reduction of the connector 202.

Further, as shown in FIG. 6, the distance E1 between the contact row251A and the second pitch side surface 263, the distance E2 between thecontact row 251F and the second pitch side surface 263, and the distanceE3 between the contact row 251D and the second pitch side surface 263satisfy the relationships of E3>E1 and E3>E2. This structure allows aspace between the contact row 251A and the contact row 251F in thevicinity of the second pitch side surface 263. This space can be usedfor forming the second nut notch 274, for example.

Further, as shown in FIGS. 7 and 8, the connector 202 further includesthe first hold-down 252 (reinforcing member) made of metal. The housing250 includes the CPU board opposed surface 250A (second board opposedsurface) to be opposed to the CPU board 201. The first hold-down 252includes the reinforcing plate part 252A that covers the CPU boardopposed surface 250A around the first positioning hole 260. Thisstructure allows the enlarging deformation of the first positioning hole260 to be inhibited by the first hold-down 252, which preventssignificant degradation of the positioning accuracy by the firstpositioning hole 260. The same applies to the second hold-down 253.

Further, as shown in FIG. 8, the first hold-down 252 is disposed in sucha way that the reinforcing plate part 252A of the first hold-down 252does not cover the inner edge 260A of the first positioning hole 260when viewed from above. In this structure, the positioning functionexerted by the first positioning hole 260 is not hindered by the firsthold-down 252. The same applies to the second hold-down 253.

Further, as shown in FIG. 4, each contact row 251 includes the pluralityof contacts 300. As shown in FIG. 12, each contact 300 includes theelectrical contact spring piece 322 that projects upward from the CPUboard opposed surface 250A. As shown in FIG. 5, the first hold-downaccommodation recess 280 (accommodation recess) that accommodates thereinforcing plate part 252A of the first hold-down 252 is formed on theCPU board opposed surface 250A of the housing 250. In this structure,the reinforcing plate part 252A of the first hold-down 252 does notproject upward beyond the CPU board opposed surface 250A, and thereforethe downward elastic deformation of the electrical contact spring piece322 is not hindered. The same applies to the second hold-down 253, thethird hold-down 254, and the fourth hold-down 255.

Further, as shown in FIG. 8, the first hold-down 252 further includesthe soldering part 252B that projects toward the input-output board 203from the reinforcing plate part 252A of the first hold-down 252 and isconnectable by soldering to the pad 215 of the input-output board 203.According to this structure, when the CPU board 201 is pressed againstthe connector 202 and thereby the housing 250 moves downward relative tothe first hold-down 252, the first hold-down 252 receives the CPU board201 and thereby restricts the further movement of the CPU board 201. Thesame applies to the second hold-down 253, the third hold-down 254, andthe fourth hold-down 255.

Second Technical Idea, No. 0174

As shown in FIGS. 1 and 2, the connector 202 (board-to-board connector)is mounted on the input-output board 203 (first board). The connector202 is interposed between the input-output board 203 and the CPU board201 (second board), and thereby the plurality of pads 215 of theinput-output board 203 and the plurality of pads 206 of the CPU board201 are respectively electrically connected to one another. As shown inFIGS. 3 to 5, the connector 202 includes the flat-plate housing 250 madeof insulating resin having the first positioning hole 209 and the secondpositioning hole 210, the plurality of contacts 300 held on the housing250, and the first hold-down 252 and the second hold-down 253 made ofmetal disposed to correspond to the first positioning hole 260 and thesecond positioning hole 261, respectively. The housing 250 includes theCPU board opposed surface 250A (second board opposed surface) to beopposed to the CPU board 201. As shown in FIG. 8, the first hold-down252 includes the reinforcing plate part 252A that covers the CPU boardopposed surface 250A around the first positioning hole 260. Likewise, asshown in FIG. 9, the second hold-down 253 includes the reinforcing platepart 253A that covers the CPU board opposed surface 250A around thesecond positioning hole 261. This structure allows the enlargingdeformation of the first positioning hole 260 to be inhibited by thefirst hold-down 252, which prevents significant degradation of thepositioning accuracy by the first positioning hole 260. The same appliesto the second hold-down 253. Further, as shown in FIG. 8, the firsthold-down 252 is disposed in such a way that the reinforcing plate part252A of the first hold-down 252 does not cover the inner edge 260A ofthe corresponding first positioning hole 260 when viewed from above. Inthis structure, the positioning function exerted by the firstpositioning hole 260 is not hindered by the first hold-down 252. Thesame applies to the second hold-down 253.

Further, as shown in FIG. 12, each contact 300 includes the electricalcontact spring piece 322 that projects upward from the CPU board opposedsurface 250A. As shown in FIG. 5, the first hold-down accommodationrecess 280 (accommodation recess) that accommodates the reinforcingplate part 252A of the first hold-down 252 is formed on the CPU boardopposed surface 250A of the housing 250. In this structure, thereinforcing plate part 252A of the first hold-down 252 does not projectupward beyond the CPU board opposed surface 250A, and therefore thedownward elastic deformation of the electrical contact spring piece 322is not hindered. The same applies to the second hold-down 253.

Further, as shown in FIG. 8, the first positioning hole 260 is a roundhole. The reinforcing plate part 252A of the first hold-down 252 has thepenetrating hole 252C (round hole) that is larger than the firstpositioning hole 260. The first hold-down 252 is disposed in such a waythat the inner edge 260A of the first positioning hole 260 is locatedradially inward with respect to the inner edge 252D of the penetratinghole 252C of the reinforcing plate part 252A of the first hold-down 252when viewed from above. According to this structure, the structure wherethe reinforcing plate part 252A of the first hold-down 252 does notcover the inner edge 260A of the corresponding first positioning hole260 is achieved in a rational way.

Further, as shown in FIG. 9, the second positioning hole 261 has theinner edge 261A including the two straight edge parts 261B that areparallel to each other. The reinforcing plate part 253A of the secondhold-down 253 has the penetrating hole 253C (hole) having the inner edge253D including the two straight edge parts 253E that are parallel toeach other. The distance 253F between the two straight edge parts 253Eof the reinforcing plate part 253A of the second hold-down 253 is longerthan the distance 261C between the two straight edge parts 261B of thesecond positioning hole 261. The second hold-down 253 is disposed insuch a way that the two straight edge parts 261B of the secondpositioning hole 261 are located between the two straight edge parts253E of the reinforcing plate part 253A of the second hold-down 253 whenviewed from above. According to this structure, the structure where thereinforcing plate part 253A of the second hold-down 253 does not coverthe inner edge 261A of the corresponding second positioning hole 261 isachieved in a rational way.

Further, as shown in FIG. 8, the first hold-down 252 further includesthe soldering part 252B that projects toward the input-output board 203from the reinforcing plate part 252A of the first hold-down 252 and isconnectable by soldering to the pad 215 of the input-output board 203.According to this structure, when the CPU board 201 is pressed againstthe connector 202 and thereby the housing 250 moves downward relative tothe first hold-down 252, the first hold-down 252 receives the CPU board201 and thereby restricts the further movement of the CPU board 201. Thesame applies to the second hold-down 253.

Third Technical Idea, No. 0167

As shown in FIGS. 1, 2 and 14, the connector 202A with a suction coverincludes the connector 202 (board-to-board connector) and the suctioncover 340 that is detachable from the connector 202. The connector 202is mounted on the input-output board 203 (first board). The connector202 is interposed between the input-output board 203 and the CPU board201 (second board), and thereby the plurality of pads 215 of theinput-output board 203 and the plurality of pads 206 of the CPU board201 are respectively electrically connected. As shown in FIGS. 3 to 5,the connector 202 includes the housing 250 made of insulating resin, theplurality of contacts 300 held by the housing 250, and the firsthold-down 252 made of metal. The housing 250 includes the CPU boardopposed surface 250A (second board opposed surface) to be opposed to theCPU board 201. As shown in FIG. 8, the first hold-down 252 includes thereinforcing plate part 252A that covers the CPU board opposed surface250A. As shown in FIG. 12, each contact 300 includes the electricalcontact spring piece 322 that projects from the CPU board opposedsurface 250A. As shown in FIGS. 14 and 15, the suction cover 340includes the flat-plate suction plate part 341 that covers theelectrical contact spring piece 322 of each contact 300 and can besucked by a suction nozzle, the plurality of attachment spring pieces342 that can catch on the connector 202 so that the suction plate part341 is detachable from the connector 202, and the first main deformationrestraining part 350 (first deformation restraining part) that projectsfrom the suction plate part 341 toward the CPU board opposed surface250A in order to inhibit the suction plate part 341 from being deformedtoward the CPU board opposed surface 250A in the state where the suctioncover 340 is attached to the connector 202. The first main deformationrestraining part 350 is disposed to come into contact with thereinforcing plate part 252A when the suction plate part 341 is deformedtoward the CPU board opposed surface 250A. This structure prevents thehousing 250 from being broken by the first main deformation restrainingpart 350 of the suction cover 340. The same applies to the second maindeformation restraining part 351, the third main deformation restrainingpart 352, and the fourth main deformation restraining part 353.

Further, as shown in FIG. 15, the first main deformation restrainingpart 350 is opposed to the reinforcing plate part 252A in the verticaldirection in the state where the suction cover 340 is attached to theconnector 202. This structure effectively prevents the housing 250 frombeing broken by the first main deformation restraining part 350 of thesuction cover 340.

Further, as shown in FIG. 14, the suction cover 340 further includes thetwo removal hooks 344. The two removal hooks 344 project outward beyondthe outer edge 354 of the connector 202 in the state where the suctioncover 340 is attached to the connector 202. This structure allowsfingers to easily catch on the removal hooks 344, which facilitates theremoval of the suction cover 340 from the connector 202. Note that oneof the two removal hooks 344 may be omitted.

Fourth Technical Idea, No. 0166

As shown in FIGS. 1 and 2, the connector 202 is mounted on theinput-output board 203 (first board). The connector 202 includes theflat-plate housing 250 made of insulating resin and the contact 300 heldon the housing 250 by press-fitting. As shown in FIG. 12, the housing250 includes the press-fitting space 301 and the solder connectionchecking hole 302. The contact 300 includes the press-fit part 320 to bepress-fit into the press-fitting space 301, and the soldering part 321that extends from the press-fit part 320 and is connected by solderingto the pad 215 of the input-output board 203. The solder connectionchecking hole 302 is formed to penetrate the housing 250 in the verticaldirection and allow the solder fillet 330, which is formed when thesoldering part 321 is soldered to the pad 215 of the input-output board203, to be checked through the solder connection checking hole 302. Thehousing 250 includes the separating wall 303 that separates thepress-fitting space 301 from the solder connection checking hole 302. Inthis structure, the presence of the separating wall 303 preventsshavings of the housing 250 that can be generated when press-fitting thepress-fit part 320 into the press-fitting space 301 from moving into thesolder connection checking hole 302. This enables checking the solderfillet 330 from above through the solder connection checking hole 302with no problem.

Further, as shown in FIG. 12, the press-fit part 320 is configured tobite into the pitch partition surface 304 (surface) that is the innersurface of the press-fitting space 301 and different from the firstseparating surface 306 (surface) constituting the separating wall 303.In this structure, no load is placed on the separating wall 303 whenpress-fitting the press-fit part 320 into the press-fitting space 301.This eases restrictions in terms of strength design of the separatingwall 303.

Further, as shown in FIG. 12, the curve part 321B of the soldering part321 is located inside the solder connection checking hole 302. Thisstructure allows the boundary between the solder fillet 330 and thecontact 300 to be checked through the solder connection checking hole302 and thereby achieves more accurate determination as to whether thesolder connection in the soldering part 321 is successfully made or not.

Note that, in FIG. 12, the continuity between the contact 300 and thepad 215 may be checked by inserting a probe needle into the solderconnection checking hole 302 and making the probe needle come intocontact with the curve part 321B of the soldering part 321, and furthermaking another probe needle come into contact with a circuit pattern ofthe input-output board 203, which is electrically continuous with thepad 215. In this case also, the movement of shavings of the housing 250that can be generated when press-fitting the press-fit part 320 into thepress-fitting space 301 into the solder connection checking hole 302 isinhibited as described above, which allows the probe needle to easilycome into contact with the curve part 321B of the soldering part 321.

Second Embodiment

A second embodiment is described hereinafter with reference to FIG. 16.Hereinafter, differences of this embodiment from the above-describedfirst embodiment are mainly described, and redundant description isomitted.

As shown in FIG. 16, the suction cover 340 according to this embodimentfurther includes two sub deformation restraining parts 360 (seconddeformation restraining parts). The two sub deformation restrainingparts 360 are respectively formed at both ends of the suction plate part341 in the pitch direction. Specifically, the two sub deformationrestraining parts 360 include a first sub deformation restraining part361 disposed on the first pitch side surface 262 side and a second subdeformation restraining part, which is not shown, disposed on the secondpitch side surface 263 side.

The first sub deformation restraining part 361 projects from the suctionplate part 341 toward the CPU board opposed surface 250A in order toinhibit the suction plate part 341 from being deformed toward the CPUboard opposed surface 250A in the state where the suction cover 340 isattached to the connector 202.

The first sub deformation restraining part 361 is disposed between thefirst main deformation restraining part 350 and the second maindeformation restraining part 351. The first sub deformation restrainingpart 361 is disposed to avoid the first nut notch 271 when viewed fromabove. The first sub deformation restraining part 361 is formed bybending a part of the suction plate part 341 downward. In other words,the first sub deformation restraining part 361 is formed to projectdownward from the suction plate part 341. The first sub deformationrestraining part 361 is disposed in such a way that a lower end 361A ofthe first sub deformation restraining part 361 is opposed to the CPUboard opposed surface 250A in the vertical direction in the state wherethe suction cover 340 is attached to the connector 202.

Thus, when the suction plate part 341 is deformed toward the CPU boardopposed surface 250A, the first main deformation restraining part 350and the second main deformation restraining part 351 come into contactwith the first hold-down 252 and the second hold-down 253, respectively,and further the first sub deformation restraining part 361 comes intocontact with the CPU board opposed surface 250A of the housing 250, andtherefore further deformation of the suction plate part 341 isinhibited. This prevents that the suction plate part 341 comes intocontact with the plurality of contacts 300 to cause the plurality ofcontacts 300 to be broken.

Note that, in the state where the suction cover 340 is attached to theconnector 202, the gap between the first main deformation restrainingpart 350 and the reinforcing plate part 252A in the vertical directionis smaller than the gap between the first sub deformation restrainingpart 361 and the CPU board opposed surface 250A in the verticaldirection. Thus, when the suction plate part 341 is deformed toward theCPU board opposed surface 250A, the first main deformation restrainingpart 350 comes into contact with the first hold-down 252 before thefirst sub deformation restraining part 361 comes into contact with theCPU board opposed surface 250A of the housing 250. Thus, when the amountof deformation when the suction plate part 341 is deformed toward theCPU board opposed surface 250A is small, the first sub deformationrestraining part 361 does not come into contact with the CPU boardopposed surface 250A, which inhibits the generation of shavings. On theother hand, when the amount of deformation when the suction plate part341 is deformed toward the CPU board opposed surface 250A is large, thefirst sub deformation restraining part 361 comes into contact with theCPU board opposed surface 250A of the housing 250 in addition to thatthe first main deformation restraining part 350 comes into contact withthe first hold-down 252, which reliably inhibits further deformation ofthe suction plate part 341 and prevents that the suction plate part 341comes into contact with the plurality of contacts 300 to cause theplurality of contacts 300 to be broken.

The same applies to the second sub deformation restraining part, whichis not shown, disposed on the second pitch side surface 263 side.Further, any one of the two sub deformation restraining parts 360 may beomitted.

Third Embodiment

A third embodiment is described hereinafter with reference to FIG. 17.Hereinafter, differences of this embodiment from the above-describedfirst embodiment are mainly described, and redundant description isomitted.

As shown in FIG. 17, the contact 300 further includes a support springpiece 370 that is disposed inside the solder connection checking hole302 and elastically comes into contact with the second separatingsurface 307 of the separating wall 303. The support spring piece 370 iselastically in contact with the second separating surface 307 of theseparating wall 303 by the elastic restoring force of the contact 300.The effect of stabilizing the posture of each contact 300 in eachcontact accommodation part 284 is thereby obtained.

The support spring piece 370 is disposed to project upward from thecurve part 321B of the soldering part 321. The support spring piece 370is inclined so as to approach the separating wall 303 as it goes upwardfrom the curve part 321B of the soldering part 321.

The press-fit part 320 is in contact with the first separating surface306 of the separating wall 303. The support spring piece 370 iselastically in contact with the second separating surface 307 of theseparating wall 303 so as to press the second separating surface 307 ofthe separating wall 303 toward the press-fit part 320. The press-fitpart 320 and the support spring piece 370 thereby elastically put theseparating wall 303 between them, and therefore the posture of eachcontact 300 is further stabilized in each contact accommodation part284.

When press-fitting the press-fit part 320 into the press-fitting space301, the support spring piece 370 moves upward, remaining in contactwith the second separating surface 307 of the separating wall 303. Thus,in this embodiment, the support spring piece 370 includes a curvedsurface 370A that is convex toward the press-fit part 320. The curvedsurface 370A is elastically in contact with the second separatingsurface 307 of the separating wall 303. In this structure, even if thesupport spring piece 370 moves upward, remaining in contact with thesecond separating surface 307 of the separating wall 303 whenpress-fitting the press-fit part 320 into the press-fitting space 301,the second separating surface 307 is less likely to be shaved by thesupport spring piece 370, which inhibits shavings of the separating wall303 from being generated in the solder connection checking hole 302.

Fourth Embodiment

A fourth embodiment is described hereinafter with reference to FIG. 18.Hereinafter, differences of this embodiment from the above-describedfirst embodiment are mainly described, and redundant description isomitted.

In the above-described first embodiment, the first nut notch 271 foravoiding the physical interference between the first nut 231 and thehousing 250 is formed on the housing 250 as shown in FIGS. 1 and 5.Likewise, the second nut notch 274 for avoiding the physicalinterference between the second nut 232 and the housing 250 is formed onthe housing 250.

On the other hand, in this embodiment, as shown in FIG. 18, a first nutpenetrating hole 380 for avoiding the physical interference between thefirst nut 231 and the housing 250 is formed on the housing 250, insteadof the above-described first nut notch 271. Likewise, a second nutpenetrating hole 381 for avoiding the physical interference between thesecond nut 232 and the housing 250 is formed on the housing 250, insteadof the above-described second nut notch 274.

Further, in the above-described first embodiment, as shown in FIG. 4,the connector 202 includes the first hold-down 252, the second hold-down253, the third hold-down 254, and the fourth hold-down 255. The firsthold-down 252, the second hold-down 253, the third hold-down 254, andthe fourth hold-down 255 are separate parts.

On the other hand, in this embodiment, as shown in FIG. 18, the firsthold-down 252, the second hold-down 253, the third hold-down 254, andthe fourth hold-down 255 are formed integrally so that they arecontinuous with one another. In this manner, by forming the firsthold-down 252, the second hold-down 253, the third hold-down 254, andthe fourth hold-down 255 as one part, high electromagnetic shield effectis obtained.

To be specific, the connector 202 includes an entire hold-down 382. Theentire hold-down 382 includes the first hold-down 252, the secondhold-down 253, the third hold-down 254, and the fourth hold-down 255.The entire hold-down 382 is formed annularly so as to surround theplurality of contacts 300 when viewed from above. The entire hold-down382 includes a reinforcing plate part 383 and a plurality of solderingparts 384.

The reinforcing plate part 383 is a part that covers the CPU boardopposed surface 250A of the housing 250. The reinforcing plate part 383includes the reinforcing plate part 252A of the first hold-down 252 andthe reinforcing plate part 253A of the first hold-down 253, for example.

The plurality of soldering parts 384 are connectable by soldering to thecorresponding pads of the input-output board 203. The plurality ofsoldering parts 384 include a first soldering part 385, a secondsoldering part 386, a third soldering part 387, and a fourth solderingpart 388.

The first soldering part 385 corresponds to the first pitch side surface262 of the housing 250.

The second soldering part 386 corresponds to the second pitch sidesurface 263 of the housing 250.

The third soldering part 387 corresponds to the first width side surface264 of the housing 250.

The fourth soldering part 388 corresponds to the second width sidesurface 265 of the housing 250.

Fifth Embodiment

A fifth embodiment is described hereinafter with reference to FIG. 19.Hereinafter, differences of this embodiment from the above-describedfourth embodiment are mainly described, and redundant description isomitted.

The first soldering part 385 according this embodiment is provided witha plurality of slits 385A that divide the first soldering part 385 inthe width direction.

Likewise, the second soldering part 386 according this embodiment isprovided with a plurality of slits 386A that divide the second solderingpart 386 in the width direction.

Likewise, the third soldering part 387 according this embodiment isprovided with a plurality of slits 387A that divide the third solderingpart 387 in the width direction.

Likewise, the fourth soldering part 388 according this embodiment isprovided with a plurality of slits 388A that divide the fourth solderingpart 388 in the width direction.

Forming a plurality of slits that divide each of the soldering parts 384in the longitudinal direction of each soldering part 384 as describedabove enables the absorption of the warpage of the input-output board203, for example, and contributes to weight reduction of the connector202.

The above-described embodiments can be combined as desirable by one ofordinary skill in the art.

From the disclosure thus described, it will be obvious that theembodiments of the disclosure may be varied in many ways. Suchvariations are not to be regarded as a departure from the spirit andscope of the disclosure, and all such modifications as would be obviousto one skilled in the art are intended for inclusion within the scope ofthe following claims.

What is claimed is:
 1. A board-to-board connector to be mounted on afirst board and interposed between the first board and a second board toelectrically connect a plurality of pads of the first board with aplurality of pads of the second board respectively, comprising: arectangular flat-plate housing including a first positioning hole and asecond positioning hole; and a first contact row and a second contactrow held on the housing, wherein the housing includes only the firstpositioning hole and the second positioning hole as positioning holesfor positioning the second board with respect to the board-to-boardconnector, the first contact row and the second contact row are disposedto separate from each other in a direction orthogonal to a longitudinaldirection of the first contact row, the housing includes a first sidesurface on one side thereof and a second side surface on another sidethereof opposite to the one side, the first contact row and the secondcontact row extend from the first side surface to the second sidesurface, the first positioning hole is disposed between the first sidesurface and the first contact row, and the second positioning hole isdisposed between the first side surface and the second contact row. 2.The board-to-board connector according to claim 1, further comprising: areinforcing member made of metal, wherein the housing includes a secondboard opposed surface to be opposed to the second board, and thereinforcing member includes a reinforcing plate part to cover the secondboard opposed surface around the first positioning hole or the secondpositioning hole.
 3. The board-to-board connector according to claim 2,wherein the reinforcing member is disposed in such a way that thereinforcing plate part of the reinforcing member does not cover an inneredge of the first positioning hole or the second positioning hole whenviewed in a thickness direction of the housing.
 4. The board-to-boardconnector according to claim 2, wherein the first contact row includes aplurality of contacts, each of the contacts includes an electricalcontact spring piece projecting from the second board opposed surface,and an accommodation recess to accommodate the reinforcing plate part ofthe reinforcing member is formed on the second board opposed surface ofthe housing.
 5. The board-to-board connector according to claim 2,wherein the reinforcing member further includes a soldering partprojecting toward the first board from the reinforcing plate part of thereinforcing member and connectable by soldering to a pad of the firstboard.
 6. The board-to-board connector according to claim 1, wherein thefirst positioning hole is a round hole, and the second positioning holeis a slotted hole.